Richmond premiership coach Damien Hardwick has put pen to paper on a new three-year deal that ties him to the AFL club until the end of the 2021 season.

Hardwick, appointed in late 2009 after Terry Wallace's sacking, is set to become the club's longest-serving coach.

The 45-year-old was mobbed by his players on Tuesday when chief executive Brendon Gale told them the news at Punt Road.

"Four finals series in five years, culminating in a drought-breaking premiership, was massive for the club," Gale said in his address.

"Huge credit to him, huge credit to the coaching department, the football department, huge credit for the extent to which he's invested and committed to you guys and huge credit to the way you've committed to him as well.

"It's obvious in the way you played (last year) so, on that basis, no surprise - we're going to extend his contract for three years out to 2021."

Hardwick, a premiership player with Essendon and Port Adelaide, has coached the Tigers in 182 AFL games and will pass club legends Tom Hafey (248 games) and Jack Dyer (222) with the new deal.

The move caps a stunning comeback for Hardwick who had been under intense pressure to keep his job when the Tigers slumped to 13th at the end of the 2016 season.

He underwent a period of reflection and soul-searching after that ill-fated campaign and adopted a fresh approach before the 2017 season that culminated in the club's first premiership since 1980.

"I'm incredibly honoured to continue coaching the Richmond Football Club and have the support of (president) Peggy (O'Neal), Brendon and the board," Hardwick said.

"It's a collective effort that helps deliver success and I'm fortunate at Richmond to have a great group of players, coaches and staff all working together towards our goal.

"It's been an exciting journey thus far at Richmond and both myself, the coaches and players are eager for the challenge that awaits this season."